We do an approximate comparison of MetNet-2 also with the MetNet model [1]}. An exact comparison is difficult due to changes in the projection of the input data that has architectural implications, as well as other differences in the test data. For this reason, we simply plot MetNet-2' and MetNet' performances on the same plot, despite the fact that they are evaluated on slightly different test datasets. MetNet was shown to exceed HRRR's performance up to 7 to 8 hours of lead time. MetNet-2 without the assimilation variables exceeds HRRR's performance for up to nearly 12 hours of lead time, as can be seen in Figure REF . This extension to 12 hours comes purely from the better architecture of MetNet-2 and an improved training regime. Using the assimilation variables as input, MetNet-2 provides a further improvement and its performance is even higher with respect to that of MetNet across the full range (Figure REF ). This is despite the fact that the baseline HRRR achieves higher F1 scores on MetNet's test data than on MetNet-2's test data and finds MetNet's test data easier to predict well.
